The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Various sculptures are a rotating exhibit in this small town.

Remarkably preserved body discovered in a peat bog.

This hotel was once home to a steamliner company and became the final rest stop for Europeans heading to the New World.

A modern reimagining of a medieval city gate.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Atop this former dutch railway office sits an interstellar work of art.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

A grassy pyramid named after a French battle.

At the base of this tower, a plaque marks the original center point of the Netherlands.

This large open-air museum showcases the ordinary lives of the people of the Netherlands and pre-industrial crafts and practices.

Located inside Hoge Veluwe National Park, this museum began as the private collection of a prominent female art collector.

This disused VLF radio station is no longer in service but the surrounding town still bears its name.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

This legendary giant, born from vegetables, terrorized townspeople and cheated local children in games.